1. Technical Field
The present invention relates generally to louvers used to control engine compartment ventilation for cooling of the compartment on a motor vehicle.
2. Description of the Problem
Elevated engine compartment air temperatures on motor vehicles have been a design issue essentially since the introduction of internal combustion engines to motor vehicles. The problem has not abated, but become worse, in recent years. This stems in part from the increasing use of exhaust gas recirculation and catalytic converters to reduce exhaust emissions. It also results from the addition of vehicle accessories such as air conditioning. Higher underhood air temperature drives component material selection, cooling system capacity and other design considerations, all of which can add to expense and vehicle complexity. Currently, the problem is solved by the addition of cooling system capacity and heavy reliance on active monitoring. Adding cooling capacity requires more space under the hood. Louver systems have also long been used to control air flow through the engine compartment to aid cooling. Increased fan speed has been used to increase air flow through the engine compartment and under the cab. Heat shields have been used to protect temperature sensitive areas.
It would be advantageous to simplify engine compartment cooling by limiting the need for human or control system intervention while, at the same time, taking advantage of monitoring of operation of a passive cooling system.